To achieve high productivity in farming, it is desirable to be able to plow acreages of large size as rapidly as possible in order to plant seeds at an optimum time. Delays in plowing oftentimes result in a great decrease in productivity, especially when weather conditions are encountered which make it necessary to postpone completion of plowing until a much later date. As a result, the use of plows having a large number of bottoms is desirable to have a large plowing width per pass. Multi-section plows as well as plows having a single frame carrying a smaller number of bottoms present problems in control of the plowing depth and systems heretofore proposed have either been complicated in construction and operation, oftentimes requiring a large number of controls, or have not achieved adequate control of plowing depths. Reliability has also been a problem in attempting to provide plows with automatic controls.